共查询到20条相似文献，搜索用时 265 毫秒
1.
2.
《天津大学学报(英文版)》2015,(4)
A series of model experiments of bucket foundations concerning suction installation and negative pressure consolidation in saturated silt were carried out in a cube steel bin at Tianjin University. The experimental results show that the silt inside the bucket has been strengthened by negative pressure, and the strengthening effect decreases with the increase of the distance from the bucket. A three-dimensional numerical model of the experiments was built by means of finite element software ABAQUS with fluid-solid coupling method. The results show that the bearing capacity of the silt inside the bucket foundation increases significantly at the former stage of negative pressure consolidation, while the increasing trend slows down over time. The rotation centers of the bucket foundation and the inner soil region tend to be closer to each other based on the consolidation. The bearing capacity of the bucket foundation is improved effectively with the increase of soil strength. The effects of negative pressure consolidation on the bearing capacity of bucket foundation were also illustrated by an actual offshore wind power project case. 相似文献
3.
姚梅红 《福建工程学院学报》2016,(3):218-222
结合工程实践,以高层建筑附建式纯地下室与主体间的沉降差控制为目标,论述嵌岩扩底灌注桩抗拔承载力的合理估算、纯地下室采用桩基应对整体抗浮不足的优化设计方法。工程实践证明,嵌岩扩底桩可显著提高单桩的抗拔承载力,其嵌岩段抗拔极限侧阻力的估算可参照承压嵌岩桩的方法,以岩石单轴饱和抗压强度标准值表达桩的极限侧阻力标准值,并乘以抗拔折减系数来取值。 相似文献
4.
Melanie C. M. Ehren David Godfrey 《Educational Assessment, Evaluation and Accountability》2017,29(4):339-362
This paper explores the impact of external accountability on four mechanisms of network-internal quality control and the properties of (mandated) inter-organizational networks. An explorative case study approach examines the external accountability of a newly established educational network (MAT) and how schools and the Trust are held accountable by the English Inspectorate of Education, Ofsted and the Department for Education (DfE), through Regional Schools Commissioners (RSCs). Analysis of documents and interviews were used to reconstruct a sequence of events over a period of five and a half years. Our findings indicate that the combination of accountability activities led to more centralized control over, and monitoring of curriculum, assessment and school improvement. This was accompanied by a pause in the growth of the Trust and the establishment of a regional structure of school collaboration. As accountability is particularly organized around individual school performance (through Ofsted inspections), this limited development of internal mechanisms of quality control around network-level outcomes. A short-term focus dominated the allocation of resources to schools in special measures or with an upcoming inspection visit. In the discussion, an alternative model is presented for network-level accountability and a set of indicators for effective accountability of collaborative arrangements. 相似文献
5.
Suction foundations have been deployed in the last three decades in a growing number of offshore developments, for bottom-fixed and floating structures, in shallow and deep waters, many of them successfully. Suction foundations, traditionally used as anchors and jacket foundations in the oil and gas industry, are now also used in the offshore renewable (wind) industry, e.g. for monopods, tripods, and jackets. When technically feasible, suction foundations are often cheaper than pile foundations. Additionally, their installation is relatively noise-free and, by applying overpressure, they can be removed during decommissioning. This paper focuses on the more complex design issues and some pitfalls related to suction foundation design. Additionally design practices and recommendations for suction caisson design, including installation and extraction feasibility, foundation resistance, settlements and response in sand, clay and layered soil profiles, will be presented for basic understanding. 相似文献
6.
Bearing Behaviors of Stiffened Deep Cement Mixed Pile 总被引：1，自引：0，他引：1
A series of investigations were conducted to study the bearing capacity and load transfer mechanism of stiffened deep cement mixed (SDCM) pile. Laboratory tests including six specimens were conducted to investigate the frictional resistance between the concrete core and the cement soil. Two model piles and twenty-four full-scale piles were tested to examine the bearing behavior of single pile. Laboratory and model tests results indicate that the cohesive strength is large enough to ensure the interaction between core pile and the outer cement-soil. The full-scale test results show that the SDCM piles exhibit similar bearing behavior to bored and cast-in-place concrete piles. In general, with the rational composite structure the SDCM piles can transmit the applied load effectively, and due to the addition of the stiffer core, the SDCM piles possess high bearing capacity. Based on the findings of these experimental investigations and theoretical analysis, a practical design method is developed to predict the vertical bearing capacity of SDCM pile. 相似文献
7.
为客车车身结构接头的设计提供理论依据,应用有限元法,通过ANSYS软件分析了接头角板对客车平面框架结构承载性能的影响,并对计算结果进行对比.结果证明,在垂直弯曲载荷下,接头处添加角板对客车平面结构承载能力影响不大;在扭转载荷下,接头处添加角板能够有效提高客车基本平面结构的承载能力. 相似文献
8.
Design of offshore wind power foundation with multi-bucket 总被引：1，自引：0，他引：1
Three- and four-bucket offshore wind power foundations with a new form of force-transferring structure are proposed in this paper, and the integrated finite element model of foundation-soil-transition structure is established by using ABAQUS. The carrying capacity of the proposed foundations is studied under vertical load, horizontal load and bending moment. It can be seen that the vertical bearing capacity of multi-bucket foundation can be roughly estimated by the vertical bearing capacity of single-bucket; the horizontal bearing capacity of the three-bucket foundation scheme is controlled by displacement, while that of the four-bucket foundation scheme is controlled by the internal forces of soils. Moreover, the carrying capacity is provided by the overall structure formed by multi-bucket before soil failure. Compared with the conventional single-bucket foundation, there are mainly tension and pressure that are applied to the multi-bucket foundation, so that the carrying capacity of the foundation can be fully utilized. The probability of soil failure can be well reduced with the proposed multi-bucket foundation, and the stress transmission of force-transferring structure is more consistent through steel beams with variable cross-section. 相似文献
9.
润滑及清洁度对滚动轴承寿命的影响程度 总被引：1，自引：0，他引：1
郑默思 《温州职业技术学院学报》2002,2(1):39-42
本通过应用滚动轴承新的寿命计算方法对不同工作条件（润滑和清洁度）下轴承寿命的对比计算，来论述润滑与清洁度对轴承寿命影响的程度，证明合理润滑与密封设计的重要性。 相似文献
10.
苏福明 《福建工程学院学报》2007,5(6):652-656
根据某大楼2根无扩底人工挖孔桩灌注的静载试验,通过埋设在桩中不同土层位置的混凝土应变传感器在各级加载下所测得的数据,分析了桩端阻力、桩侧摩阻力的发挥规律和桩的变形规律,研究了人工挖孔桩的承载特性和荷载传递机理.试验结果表明,对嵌入软质岩有一定深度的人工挖孔桩,其桩的荷载传递性状呈现为摩擦桩的特点.根据这一特点,建议在人工挖孔桩设计前应对桩进行承载力试验,当桩端嵌入岩层一定深度时可不设计扩大头. 相似文献
11.
《天津大学学报(英文版)》2017,(5)
A hydraulics model is built in Moses to find the optimal internal skirt spacing for the maximum floating stability of the skirted foundation. The results show that the increase in the internal skirts' number can help improve the floating stability of the skirted foundation. However, with the increase in the internal skirts' number, the improvement of floating stability becomes more and more weak. In this study, an optimal number of four are found for the internal skirt spacing. Moreover, to testify the feasibility of internal skirt spacing, a practical project is modeled, which indicates that the optimal internal skirt spacing can satisfy the requirements of towing. 相似文献
12.
通过9根表层嵌入碳纤维增强塑料板条抗剪加固的钢筋混凝土梁和4根对比梁的静载试验,分析了构件的破坏形态、斜截面纤维应变分布特征及加固后极限承载力的影响因素。研究结果表明：嵌入式加固与外贴加固相比,可以明显地提高钢筋混凝土梁的抗剪承载力,并改变构件的变形性能。最后,在国内外研究资料的基础上,提出了加固后混凝土梁的受剪承载力计算公式,并对计算值与试验值进行了比较,结果吻合较好。 相似文献
13.
In this study, nine simplified short composite columns consisting of core CFST (concrete filled steel tube) of different diameters and outer reinforced concrete were constructed to study their compressive performance under axial or eccentric compression. The failure mode is characterized by the crush of the outer concrete. The bearing capacity increases at first and then decreases with further increase of the position coefficient. It can be concluded that position coefficient is an important structural parameter that has considerable influences on the ultimate bearing capacity of the composite columns. The outer concrete, steel tubes and longitudinal reinforcement are found to work in a cooperative manner under axial or eccentric compression when the position coefficient is about 0.5. An improved bearing capacity algorithm that takes the position coefficient into account has been proposed based on the experimental and simulation results and current technical specification in China. It has been proven to be precise and safe. 相似文献
14.
英语作格动词具有主动形式被动意义特征,是词汇语义句法范畴内讨论的热点问题。就词汇语义性质来说,作格动词属于强动作性使役动词,具有动作自发性,不需要外力作用,不允许增加被动语法标记。然而人们往往错误地将其用于被动语态,这是混淆作格动词与被动词的语义特征的表现。根据词汇语义结构理论,通过对作格动词词汇语义特征的分析,解释作格动词与被动词及其句式的异同,提出作格动词不可用于被动语态主要与其具有被动意义特征相关。 相似文献
15.
Bucket foundations[1 ,2]are a relatively newtype offoundation usedto support offshore structures .Each bucketfoundation consists of a thin cylindrical steel shell ,cappedwithalid of steel or concrete .Thefoundationcan penetrateinto sea floor when pumping … 相似文献
16.
17.
古代汉语被动句有多种形式,可以分成意念被动和标记被动两类,它们有共同的特征：及物动词谓语不带宾语,语法结构与语义结构矛盾。被动句形式变化的动因是避免歧解,变化朝准确性和完备性方向发展。带宾语的被动式的存在,是与双宾语句等特殊的主动句相应。 相似文献
18.
杨光煦 《长江工程职业技术学院学报》1999,(2)
总结了九江江堤溃口段复堤设计经验。阐述堤防地基渗流控制应确保有一定渗径长度,防止产生渗透破坏,减少作用在防洪墙底板上的扬压力。采用迎水侧具有隔渗作用的格栅状深层搅拌桩结构,可提高地基承载力,消除不均匀沉降,确保地基抗滑及抗渗稳定。 相似文献
19.
裴碧峰 《福建工程学院学报》2005,3(1):66-70
深入分析了“顺穿法”和“花穿法”绕制的单行并联式滑车组在起重工作时的受力性能，通过对滑车组的偏心距和倾斜角计算，证明偏心距及倾斜角较大时对滑车组的工作和使用寿命存在很不利的影响。详细分析了混联式滑车的构造和受力性能，并对其起重时的偏心及倾斜角进行了计算，计算结果表明该新型滑车组在构造和技术上具有明显的优越性。混联式滑车于1996年获得国家发明专利。 相似文献
20.
本文从县级土地资源生产潜力估算方法入手,分别估算了××县各乡(镇)耕地与林地生产潜力,并在此基上础,估算了该县的人口承载量,结果表明,××县理论承裁力为1608327(人),其中耕地承裁723211(人);林地承裁885116(人),若按目前人口增长率增长,则24年后亦即2013年××县人口将达到饱和,由此可见××县土地人口承裁力不容乐观。 相似文献